Screw Conveyor for Metal Chips

General Description

With over 5,000 customers, Calbag Metals Company provides non-ferrous metal recycling services for a wide range of companies and consumers. Calbag purchases scrap metal from the general public, tradesmen, industrial manufacturers, and scrap yards all along the West Coast. After unwanted debris is removed, the metal is shredded for ease of handling, sorted by metal composition, and sold to hundreds of customers. Calbag is the fastest-growing buyer, seller, and trader of non-ferrous scrap metal in the Pacific Northwest.

In 2010, Calbag and KWS successfully worked in partnership on a large-scale project to improve the conveying equipment in their Portland facility. KWS provided several screw conveyors, screw feeders, bucket elevators, and various transition chutes. When it became time for another production modification, Calbag contacted KWS for assistance in providing the ideal conveying solution. The modification required the replacement of an existing belt conveyor with a new inclined screw conveyor. The new screw conveyor receives metal chips from a reinforced granulator via vibratory conveyor then elevates the copper and aluminum chips to a separation table. The screw conveyor is fitted with a special inlet chute as it is preceded by a drum magnet to remove any ferrous metals. KWS also provided a manual 2-way, “K” style diverter valve at the conveyor’s discharge to give Calbag the ability to select the path of the material when the separation table is not required.

Design Parameters

1. Product Type: Aluminum or Copper Chips
2. Material Density: 55 Lbs. per Cubic Foot
3. Conveyor System Capacity: 364 Cubic feet per Hour
4. Duty: Intermittent

KWS Advantages

At Calbag’s request, the KWS engineering team collaborated with the manufacturers of other process equipment to ensure the modification would be successful. The engineers from all companies were able to exchange 3D parametric models to ensure the equipment would fit together in the field seamlessly. Weekly conference calls kept the project on-time and enabled KWS to deliver the equipment to meet Calbag’s critical installation schedule.

Special Features

KWS utilized a specially designed Torque Arm Trough End for use with a right-angle gearmotor. The KWS Torque Arm Trough End incorporates the use of a pillow block roller bearing that supports the single-piece screw and acts as a thrust bearing. Utilizing a pillow block bearing allows for the use of a split gland shaft seal and removes the torsion and bending loads from the gearmotor output bearings.

As with all screw conveyors at Calbag, KWS used a stub end shaft to eliminate material leakage or premature seal and bearing failure. The KWS stub end shaft is mounted using a completely leak-free gasketed mounting plate and projects internally into the screw. The tail end of the conveyor screw contains an internal bronze bushing for the bearing surface. The stub shaft is drilled for an air purge to remove any particulate.

KWS used abrasion resistant (AR400) plate for the diverter body and slide plate to increase abrasion resistance and extend wear life. The wear parts can be easily replaced through a bolted access door located on the side of the diverter housing. The manual diverter valve lever shows direction of flow, allows for quick direction selection, and is locked in placed using wing nuts for easy use.